1. Field of the Invention
The present invention relates to a seatbelt through-anchor through which a webbing for restraining an occupant is inserted and to a seatbelt device including the seatbelt through-anchor.
2. Description of the Related Art
A seatbelt device is installed to a seat of a vehicle. The seatbelt device is a safety device that restrains an occupant using a webbing, and prevents the occupant from being propelled forward by inertial force when a large deceleration acts on the vehicle due to a sudden stop or a collision.
The webbing is pulled out upward inside the vehicle from a retractor that winds up the webbing, passed through a through-anchor fixed to a vehicle body, and folded back downward inside the vehicle. An anchor plate to be fixed to a lower part of the interior of the vehicle is attached to a tip part of the folded-back webbing.
In addition, a tongue plate through which the webbing is inserted and which is capable of sliding over the webbing is arranged between the through-anchor and the anchor plate. Furthermore, a buckle is provided at a side part (center side of the vehicle) of the vehicle seat.
A worn state of the seatbelt device is created as the occupant grasps the tongue plate, pulls out the webbing from the retractor, and inserts the tongue plate into the buckle, whereby the seatbelt device restrains the occupant with the webbing.
With such a seatbelt device, there is a problem that so-called jamming occurs in which, during an emergency such as a collision of a vehicle, a webbing that is abruptly wound up by or pulled out from a retractor is moved to one side of an insertion hole of a through-anchor. Once jamming occurs, the webbing can no longer be pulled out or wound up in a smooth manner.
Japanese Patent Application Laid-open No. 2002-208043 describes a through-anchor provided with a protrusion on a vehicle exterior side or a wall side of a vehicle interior of the through-anchor. The through-anchor is intended to prevent jamming by hooking a webbing to the protrusion of the through-anchor.
Japanese Patent Application Laid-open No. 2000-142317 describes a through-anchor which is provided with a protrusion (straightening plate) on a vehicle interior side of the through-anchor and which is configured to prevent a webbing from twisting when the webbing is wound up after an occupant removes the webbing.